Steam-engine dash-pot.



No. 662,0!1. Patented Nov. 20, |900. M. R. MOORE.

STEAM ENGINE DASH POT.

(Aapucion med Jg. 19, 1900. (No Model.)

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Unire' STATES ATENT OFFICE..l

MATTHEW ROBERT MOORE, OF INDIANAPOLIS, INDIANA, ASSIGNOR TO THE ATLAS ENGINE WORKS, OF SAME PLACE.

STEAM-ENGINE DASH-POT.

SPECIFICATION forming part of Letters Patent No. 662,011, dated November 20, 1900.

Application filed January 19, 1900. Serial No. 1.989. (No model.)

To @ZZ whom t may con/067%:

Be it known that I, MATTHEW ROBERT MOORE, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain Improvements in Steam-Engine Dash-Pots, of which the following is a specification.

My improved dash-pot may be used with steam of' any pressure; but it should be al- 1o lowed to have a large diameterifintended to be used with steam of very moderate pressure, because the active force to effect the shutting motion ofthe valve is derived from the direct action of the steam on the movable part,

usually termed a piston, therein. I will show such piston as packed but it will be understood that packing is not essential.

In what I esteem the most complete form of the invention I employ two dash-pots and 2o links for each of the steamvalves. In oneI let the steam flow freely through a liberal opening in the axial line of the piston and make the piston of two widely-differing diameters, arranging it to play to the considerable distance required to shut the valve in a corresponding cylinder of two diameters. The area which is effective is the annular excess ofthelargeroverthesmallerdiameter. When my invention is thus carried out, the pressure 3o of the steam on that annulus contributes to close the valve.

I mount the cylinder and piston in close connection with the valve, using a rolling valve, and I connect to the valve ata point near its mid-length, by which I mean near the mid-length of its axis. The link between the valve and the piston allows a very easy connection and disconnection for examination or repairs. I provide for catching and retaining 4o or leading harmlessly away the small quantities of water or oil, or both, which are liable to be thrown out by the active movements of the air.

I will proceed to describe what I consider the best means of carrying out my invention.

The accompanying drawings form a part of this specification.

Figure l is a central vertical cross-section with the valve in the act of closing. Fig. 2

5o isa section ofa smaller portion with the valve open. Fig. 3 is a corresponding section showing another and simpler form.

Fig. 4 is a corresponding sect-ion showing still another modification.

The drawings show the novel parts with so much of the ordinary parts as is necessary to fully understand the construction. There are, as usual, two steam-valves opened and closed independently. As each is a counterpart of the other,a represen tation and minute 6o description of one will suffice for both.

Similar letters of reference indicate like parts in all the figures where they appear.

Referring to Figs. 1 and 2, A is the upper part of one end of the main cylinder of a horizontal Corliss steam-engine, and a is the port through which steam is received from the boiler or boilers through the valve-chamber b, iu which latter is mounted a rocking valve B, mounted loosely on a flattened shaft 7o through which the valve is rocked by mechanism outside to effect the turning of the valve to open the port and the releasing of the valve to allow it to close, all conforming so far to long-known and much-approved forms of Corliss mechanism. The loose connection to the flat shaft allows the valve to rise in case through the pressure of water in the cylinder or other cause there shall be an excess ofpressure in the cylinder, so as to in- 8o duce a flow backward in the direction from the cylinder toward the boiler. The valve B may have any usual form adapted to properly cover and uncover the port, the only novelty in this portion of the mechanism being short arms B and B2, madeintegral with the valve B at about the mid-length thereof, each carrying a knuckle on its end.

Oonfining our attention for a time to the arm B and the knuckle thereon, D is a link 9o adapted to endure an endwise compressive strain sufficient to promptly turn the valve. The lower end is stronglyand fleXiblyjoined to the arm B by the knuckle thereon. The upper end of the link is finished hemispherical and matches in a corresponding inverted hemispherical seat in a hollow trunk-piston having its small and large parts (designated by supernumerals E E2) adapted to move tightly and easily up and down in a correroo spending fixed cylinder A A2. A liberal aperture e extends longitudinally through. The

Y pressure.

cylinders A A7l open at their bases into the valve-chamber l), so that the steam fills the interior e of the two-part hollow piston and also the top of the cylinder A at about the boiler- The upward pressure on the small piston E', tending to urge the piston upward, balances'the downward pressure on a corresponding area in the top of the large piston E2; but the pressure of steam on the remainder of the upper surface (the annular area outside of such balanced portion) is effective in urging the piston down and by its action leverwise on the arm B turning the valve B in the direction indicated by the arrow to effect its closing. Y

The annular space in the lower part of the large cylinder A2 communicates with the eX- ternal atmosphere through a series of holes d2, located at such level that when the valve Bis forcibly turned into the open position (the opposite direction to that shown by the arrow) it by the link D lifts the piston and air enters the annular space through the holes CL2, and when the mechanism (not shown) releases the valve-shaft the strong pressure of the steam on the unbalanced portion of the piston rotates the valve promptly into the closed position. The air in the annnlarspace escapes freely through the holes a2 during the first portion of this motion, but when the piston E has sufficiently descended covers the holes a2, and the air below being imprisoned and compressed resists the further descent and gently arrests the motion. F is a cock leading from the extreme bottom of the annular space. This may be slightly opened or closed, as found to be required, to allow the imprisoned and resisting air to escape more or less freely to modify the arresting of the motion after the valve has reached the closed position. The strong and repeated flow of air outward through the holes a2 is liable to carry out sufficient oil or water, or both, to trickle down and make the outer surfaces unsightly. AX is a lip of metal cast around the lower portion of the upper cylinder A2, adapted to catch such liquid. A small pipe K conveys the liquid away.

The downward force received through the link D is in the same direction as the direct pressure of the steam on the valve B. It tends to increase the friction and `wear of the valve. I provide the other arm B2 on the opposite side of the valve, to which is knuckled a link H, knuckled to another piston I, which, play ing to the required small extent in a corresponding cylinder, receives the pressure of the steam on its under face and exertsa lifting force on the valve. The force received through this link tends to turn the valve in the same direction as that received through the other; but instead of increasing the pressure of the valve upon its seat its tensional force lifts, and thus reduces the friction.

The piston I is of ordinary form-a single diameter. So is the cylinder A8 in which it plays. The piston is tight. Both ends of the link H are knuckled, one end to the arm B2 on the valve B and the other knnckled to the piston I.

The piston E is connected to the link D by simply receiving the4 rounded end of the link in a concavity in the center of a cross-bar in the piston. The pressure of the piston being always downward makes this connection efficient. The freedom of separation when desired is im portant, because it often becomes necessary to separate the parts for examination or repairs. The separation is effected by simply lifting the piston out of engagement.

Modifications maybe made without departing from the principle or sacrificing the advantages of the invention. I have shown a form of valve which openstwo passages for the. flow of steam when the valve is` turned into the open position. The earlier-used form, giving only one opening` may be substituted. When the valve is turned into the open position, so that strong steam fills the throat under it, the downward pressure of the steam on the top of the valve is so nearly balanced that the upward pull of the link H is liable, except for the other parts, to lift it bodily to a small extent away from its seat. It descends again instantly after being turned into the closed position. An engine equipped with myinvention in this form may work with success in every respect, except for the defect highly appreciated by careful engineers, that the violent dropping of the valve upon its seat at each stroke makes a perceptible noise and might prevent the attendant from hearing indications of derangements.

Parts of the invention can be used with some success without the whole. I can dispense with the pipe K and get rid of the oil and water by wiping out the lip AX at intervals. I can even dispense with one piston and link and operate with the other piston and link alone. Figs. 3 and 4 show such constructions; but the duplication of parts,as

shown in Fig. l, having one piston lifting and the other depressing, is what I esteem the fullest development of the invention.

I claim as my inventionl. In a steam-engine the combination with a cylinder mounted on the steam-chest, of a trunk dash-piston working therein and having a longitudinal steam-aperture and operating a suitable valve substantially as set forth.

2. In a steam-engine, the combination of a piston of two diameters, having a longitudinal steam-aperture and working in a corresponding cylinder, A' A2 mounted on the steam-chest and provided with apertures a2, arranged to be covered and uncovered by the movements of the piston, the latter operating a suitable valve, substantially as set forth.

3. In a steam-engine, a rocking valve mounted on a fiat rocking shaft with liberty to leave its seat and having a. lateral arm at right an gles to the plane of the shaft within the valvechest, in combination with a link pivoted t0 IOO IIO

such arm and a connected piston subject to the steam-pressure operating through the link to turn the valve-arm in the direction to close the valve all arranged for joint operation substantially as herein speciiied.

4. In a steam-engine, a rocking valve having a lateral arm within the valve-chest, in combination with a link pivoted to such arm and a piston containing a longitudinal aperture directly communicating with the steam in the valve-chest said link transmitting motion between the valve and piston, substantially as set forth.

5. In a steam-engine, a rocking valve having a lateral arm within the valve-chest, in combination with a link, pivoted to such arm and a piston containing` a longitudinal aperture directly communicating with the steam in the valve-chest, said piston having a simple rolling contact with the link thus permitting ready detachment when required all substantially as set forth.

(S. In a steam-engine, a rocking valve having` a lateral arm within the valve-chest, in combination with a link pivoted to such arm, a piston of two diameters, having a longitudinal steam-apertu re and working in a corresponding cylinder A' A2 provided with apertures a2, arranged to be covered and uncovered by the turning of the valve, substantially as set forth.

7. In a steam-engine, a rocking valve having a lateral arm within the valve-chest, in combination with a link pivoted to such arm and connected piston subject to the steampressure operating through the link to turn the valve-arm in the direction to close the valve, such piston being of two diameters working in a corresponding cylinder A A2 providedwith apertures d2 arranged to be covered and uncovered by the turning of the valve and the link having a simple rolling contact with the piston thus being free to be easily detached from the piston when required all substantially as set forth.

8. In a steam-engine, a rocking valve hav-- ing a lateral arm within the valve-chest, in combination with a link pivoted to such arm and connected piston subject to the steampressure operating through the link to turn the valve-arm in the direction to close the valve, such piston being of two diameters working in a corresponding cylinder A' A2 provided with apertures d2 arranged to be covered and uncovered by the turning of the valve and with a lip AX adapted to arrest any water and oil ejected through such apertures, all substantially as set forth.

9. In a steam-engine, a rocking valve having a lateral arm within the Valve-chest, in combination with a link pivoted to such arm and a connected piston subject to the steampressure operating through the link to turn the valve-ar'm in the direction to close the valve, such piston being of two diameters working in a corresponding cylinder A A2 provided with apertures CL2 arranged to be covered and uncovered by the turning of the valve and with a lip AX and the pipe K adapted to arrest and lead away any Water and oil ejected through such apertures all combined and arranged to serve substantially as herein specified.

lO. In a steam-engine, arocking valve having a lateral arm within the valve-chest, in combination with a link pivoted to such arm and a connected piston subject to the steampressure operating through the link to turn the valve-arm in the direction to close the valve and a second arm on the valve also within the valve-chest extending in the opposite direction from the first and having a connected link and piston arranged to contribute to turn the valve also into the closed position, the tendency of one piston being to crowd the valve upon its seat and of the other to balance such tendency by exerting a force tending to lift the valve off its seat, all combined and arranged for joint operation substantially as herein specified.

In testimony that I claim the invention above set forth I affix my signature in presence of two witnesses.

MATTI-IEW ROBERT MOORE.

Witnesses:

FRANK H. YoUNT, FRANK Z. SHERER. 

